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Applicability of an improved Trolox equivalent antioxidant capacity (TEAC) assay for evaluation of antioxidant capacity measurements of mixtures
Abstract
The TEAC (Trolox equivalent antioxidant capacity) assay is based on scavenging of 2,2′-azinobis-(3- ethylbenzothiazoline-6-sulfonate) radical anions (ABTS−). In this report we describe a modification based on pre-generation of the ABTS radical anions with a thermolabile azo compound, 2,2′-azobis- (2-amidinopropane)HCl (ABAP). This modification makes the assay less susceptible to artefacts, e.g. influence on the radical generation process. For most antioxidants tested, a biphasic reaction pattern was seen, i.e. a fast and slow scavenging rate. We evaluated application of the assay with both lipophilic and hydrophilic compounds with antioxidant capacity. Several organic solvents, compatible with water, were tested with α-tocopherol, quercetin and β-carotene. It was found that the TEACs differed in various solvents. Under standardized conditions additivity of TEACs obtained from individual antioxidants could be demonstrated. This might enable application of the assay for the identification of “unknown” antioxidants.
... Two lipoprotein supplements manufactured from adult bovine serum were studied, one of which was exclusively manufactured using serum originated from New Zealand (NZ lipoprotein supplement), and the other was manufactured exclusively from serum originated from the United States (US lipoprotein supplement). Twenty-two batches of NZ lipoprotein supplement (batches 1-22) and 14 batches of US lipoprotein supplement (batches [23][24][25][26][27][28][29][30][31][32][33][34][35][36] all from the same vendor were used in this study. Both lipoprotein supplements share a common manufacturing process, only the source of the serum differs. ...
... Each batch was tested in absence and in presence of Trolox 25 mg/L. Trolox is a watersoluble analog of vitamin E known for its antioxidant properties, 36 the prevention of lipid peroxidation 37 and the prevention of oxidative stress-induced apoptosis. 38 Since oxidative stress and oxidized lipids are known to trigger cell death through apoptosis and ferroptosis pathways, 39 F I G U R E 2 Impact of batch-to-batch variability of lipoprotein supplement on monoclonal antibody titer. ...
... These results suggest that some compounds present in low-performing batches trigger an apoptosis pathway, and their action is partly inhibited by Trolox. Trolox is known for its antioxidant properties, 36 the prevention of lipid peroxidation 37 Despite not being able to identify the precise chemical compounds, raw-material degradation, or alteration causing the lowperforming lipoprotein supplement batches, this investigation has increased the understanding on lipoprotein supplement composition, its sensitivity to oxidation and its impact on process performance. A fingerprinting method, based on UV spectroscopy, able to monitor lipoprotein oxidation and to detect with confidence low-performing lipoprotein batches has been proposed. ...
A challenging aspect with the use of the Sp2/0 hybridoma cell line in commercial manufacturing processes of recombinant therapeutic proteins is their exogenous lipids requirement for cell proliferation and optimal protein secretion. Lipids are commonly provided to the culture using serum or serum‐derivatives, such as lipoprotein supplement. The batch‐to‐batch variability of these non‐chemically defined raw‐materials is known to impact cell culture process performance. Lipoprotein supplement variability and its impact on fed‐batch production of a recombinant monoclonal antibody (mAb) expressed in Sp2/0 cells were studied using 36 batches from the same vendor. Several batches were associated with early viability drops leading to low process performance during fed‐batch production. Increased caspase‐3 activity (an indicator of apoptosis) was correlated to viability drops when low‐performing batches were used. Addition of an antioxidant to the culture limited the increase in caspase‐3 activity. Physicochemical characterization of batches confirmed that lipoproteins are mainly composed of lipids and proteins; no clear correlation between low‐performing batches and lipoprotein supplement composition was observed. Controlled lipoprotein oxidation leads to lipoprotein solution browning, increasing absorbance at 276 nm and results in poor process performance. Because low‐performing batches absorb more at 276 nm than other batches, oxidized lipids were suspected to be the root cause of low‐performing batches. This study increased the understanding of lipoprotein supplement composition, its sensitivity to oxidation and its impact on process performance.
... Mixotrophic, batch 2.1 Liu and Lee 2000 [17] Chlorococcum sp. Mixotrophic, batch 0.7 Ma and Chen 2001 [18] Haematococcus pluvialis CCAP34/7 Photoautotrophic, batch 2. 7 Harker et al. 1996 [19] Haematococcus pluvialis SAG19-a Photoautotrophic, batch 2.0 Brinda et al. 2004 [20] Haematococcus pluvialis NIES-144 Photoautotrophic, batch 2.4 Zang et al. 2016 [21] Haematococcus pluvialis JNU35 Mixotrophic, batch 5.6 Wang et al. 2019 [22] Haematococcus pluvialis NIES-144 Photoautotrophic, batch 7.7 Kang et al. 2005 [23] [32] β-carotene 1.61 ± 0.07 Van der Berg et al. 1999 [33] Lycopene 2.31 ± 0.07 Van der Berg et al. 1999 [33] Zeaxanthin 1.70 ± 0.05 Van der Berg et al. 1999 [33] Lutein 1.40 ± 0.04 Miller et al. 1996 [32] β-criptoxanthin 1.65 ± 0.02 Van der Berg et al. 1999 [33] Self-emulsifying drug delivery systems (SEDDS) are homogeneous, isotropic, thermodynamically stable dispersions formed by oil, surfactant and co-surfactant / co-solvent. These form nano-emulsions with low energy demand. ...
... Mixotrophic, batch 2.1 Liu and Lee 2000 [17] Chlorococcum sp. Mixotrophic, batch 0.7 Ma and Chen 2001 [18] Haematococcus pluvialis CCAP34/7 Photoautotrophic, batch 2. 7 Harker et al. 1996 [19] Haematococcus pluvialis SAG19-a Photoautotrophic, batch 2.0 Brinda et al. 2004 [20] Haematococcus pluvialis NIES-144 Photoautotrophic, batch 2.4 Zang et al. 2016 [21] Haematococcus pluvialis JNU35 Mixotrophic, batch 5.6 Wang et al. 2019 [22] Haematococcus pluvialis NIES-144 Photoautotrophic, batch 7.7 Kang et al. 2005 [23] [32] β-carotene 1.61 ± 0.07 Van der Berg et al. 1999 [33] Lycopene 2.31 ± 0.07 Van der Berg et al. 1999 [33] Zeaxanthin 1.70 ± 0.05 Van der Berg et al. 1999 [33] Lutein 1.40 ± 0.04 Miller et al. 1996 [32] β-criptoxanthin 1.65 ± 0.02 Van der Berg et al. 1999 [33] Self-emulsifying drug delivery systems (SEDDS) are homogeneous, isotropic, thermodynamically stable dispersions formed by oil, surfactant and co-surfactant / co-solvent. These form nano-emulsions with low energy demand. ...
... Mixotrophic, batch 2.1 Liu and Lee 2000 [17] Chlorococcum sp. Mixotrophic, batch 0.7 Ma and Chen 2001 [18] Haematococcus pluvialis CCAP34/7 Photoautotrophic, batch 2. 7 Harker et al. 1996 [19] Haematococcus pluvialis SAG19-a Photoautotrophic, batch 2.0 Brinda et al. 2004 [20] Haematococcus pluvialis NIES-144 Photoautotrophic, batch 2.4 Zang et al. 2016 [21] Haematococcus pluvialis JNU35 Mixotrophic, batch 5.6 Wang et al. 2019 [22] Haematococcus pluvialis NIES-144 Photoautotrophic, batch 7.7 Kang et al. 2005 [23] [32] β-carotene 1.61 ± 0.07 Van der Berg et al. 1999 [33] Lycopene 2.31 ± 0.07 Van der Berg et al. 1999 [33] Zeaxanthin 1.70 ± 0.05 Van der Berg et al. 1999 [33] Lutein 1.40 ± 0.04 Miller et al. 1996 [32] β-criptoxanthin 1.65 ± 0.02 Van der Berg et al. 1999 [33] Self-emulsifying drug delivery systems (SEDDS) are homogeneous, isotropic, thermodynamically stable dispersions formed by oil, surfactant and co-surfactant / co-solvent. These form nano-emulsions with low energy demand. ...
... Ethanol was used as the blank control instead of the reaction buffer. The absorbance was measured at 450 nm using a microplate reader (TECAN, Mannedorf, Switzerland) after 30 min of incubation [19]. ...
Recent assessments of the correlations between food and medicine underscore the importance of functional foods in disease prevention and management. Functional foods offer health benefits beyond basic nutrition, with fresh fruits and vegetables being particularly prominent because of their rich polyphenol content. In this study, we elucidated the phytochemicals in ice plant (Mesembryanthemum crystallinum), a globally consumed vegetable, using an LC-QTOF/MS-based untargeted detection method. The phytochemicals were clustered based on their structural similarity using molecular networking and annotated using the in silico tool for network annotation propagation. To identify the bioactive compounds, eight compounds were isolated from ice plant extracts. These compounds were identified using extensive spectroscopic methods, including 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Additionally, we evaluated the antioxidant and anti-inflammatory activities of all the isolates. Among the tested compounds, three showed antioxidant activity and all eight showed anti-inflammatory activity, demonstrating the potential of ice plant as a functional food.
... The sample's antioxidant potential to avert ABTS oxidation is compared to trolox and is quantified in mM trolox equivalents. 14,15 • DPPH radical scavenging assay It involves use of DPPH, a constant free radical with a purple color, the intensity of which is spectrophotometrically measured at 517 nm. Antioxidants of the sample diminish DPPH to 1,1-diphenyl-2-picryl hydrazine. ...
Cardiovascular diseases, particularly hyperlipidemia, remain a significant global health concern, prompting the need to investigate alternative therapeutic approaches. This research focuses on the pharmacognostic and phytochemical evaluation of an innovative polyherbal formulation developed for its potential antihyperlipidemic properties. The pharmacognostic assessment thoroughly examines the morphological, microscopic, and macroscopic characteristics of the individual plant constituents utilized in the formulation. Additionally, organoleptic properties were utilized to set quality parameters. Subsequent phytochemical analysis aimed to recognize and enumerate bioactive moities present in the formulation. Customary procedures were employed to levy the charisma of alkaloids, flavonoids, phenolic compounds, saponin, terpenoids, and other secondary metabolites recognized for their therapeutic potential. Antioxidant assays were conducted for both individual components and the herbal tablet. The study delves into the synergistic interactions among the constituents to pinpoint and quantify specific chemical compounds responsible for the antihyperlipidemic effects. The outcome of this analysis offer broad indulgence of polyherbal formulation’s pharmacognostic and phytochemical traits, laying the groundwork for its therapeutic potential in managing hyperlipidemia.
... Actividad Antioxidante por el radical ABTS El efecto antioxidante de las muestras sobre el ABTS se evalúo siguiendo la metodología propuesta por Van den Berg (1999). Primeramente, la mezcla de una solución acuosa de persulfato potásico de 140 mM y ABTS a 7 mM, se dejó reposar de 12 a 14 h a 4°C y en la oscuridad. ...
El presente trabajo tiene el objetivo en extraer compuestos bioactivos como los fenoles provenientes de la flor de la jamaica para elaborar microcápsulas utilizando maltodextrina, caseinato de sodio y suero de leche como materiales de pared en diferentes concentraciones y aplicarlas en un yogurt para evaluar la estabilidad de los microencapsulados dentro una matriz alimentaria. Los tratamientos que se aplicaron al yogurt fueron las distintitas microcápsulas que a continuación se describen: T1: Yogurt natural sin micocápsulas, T2: Yogurt natural con extracto de flor de jamaica encapsulado con suero de leche, T3: Yogurt natural con extracto de flor de jamaica encapsulado con suero de leche y 10% solidos de maltodextrina. T4: Extracto de flor de jamaica encapsulado con suero de leche y 10% solidos de caseinato de sodio. Donde las variables de respuesta analizadas fueron: Contenido de fenoles totales, actividad antioxidante para el radical ABTS y DPPH; así mismo se realizó una prueba sensorial de nivel de agrado orientada a consumidores. El contenido total de fenoles y la actividad antioxidante de los extractos mostró que el mejor tratamiento para conservar los compuestos fenólicos de la flor de jamaica fue el T2, mismo que presento la mayor aceptación por parte del consumidor para los atributos sabor, color, aroma y textura. Por lo que la aplicación de suero de leche como material encapsulante para elaborar microcápsulas de extractos de flor de jamaica para aplicarlos en una matriz alimenticia resulta una opción viable para elaborar alimentos funcionales.
... The ABTS radical-scavenging activity of the ethanol extract was determined using the methods of van den Berg et al. (1999), Duo-Chuan (2006), and Re et al. (1992) with modifications. Briefly, a stock solution of 7.4 mM ABTS and 2.6 mM potassium persulfate was stabilized for 16 h at room temperature before use, then the mixture was diluted with PBS buffer to 0.7 absorbance units at 734 nm. ...
An ethanol extract of Lasius fuliginosus ant nests was found to be highly effective against nosemosis
in apiary honey bees. Two concentrations of the extract (300 mg and 1500 mg/100 ml sugar syrup) were tested
on honey bees infected by nosemosis, and both significantly reduced the number of Vairimorpha ceranae DNA
copies. Administration of the extract also had a positive effect on the honey bees’ immune system, increasing the
expression of genes encoding immune peptides (abaecin, defensin-1, hymenoptaecin). The extract was subjected
to detailed biochemical analysis for the presence of total carbohydrates (22.1 μg/ml), proteins (26.7 μg/ml), and
phenolic compounds (63.8 μM) and also to assess its reducing activity (69.2% for DPPH radicals and 94% for
the ABTS method). FTIR analysis revealed a number of groups and types of organic compounds (including
fatty acids, triglycerides, formic acid, and phenols), the presence of which may have a decisive influence on the
preparation’s high level of biological activity.
... ABTS assay was estimated by the procedure outlined by Van den Berg et al. [26], modified by John and Shahidi [27]. Stock solutions of 2.0 mM ABTS and 2.5 mM AAPH are prepared in 0.1 M phosphate buffer saline (pH 7.4, 0.15 M NaCl). ...
The valourization of banana by-products is an area where extensive research has been undertaken. However, there is a need to thoroughly probe into their bioactive components and nutraceutical properties for utilization in the food industry. The present study is an attempt to evaluate the phytochemical composition and nutraceutical properties of ethanolic extracts of banana pseudostem and inflorescence of three popular cultivars in Kerala, a state in South India. Palayankodan (Musa × paradisiaca Mysore AAB group), Nendran (Musa × paradisiaca AAB group), and Njalipoovan (Musa × paradisiaca AB group) were the cultivars of interest. The extracts were found to be good source of phytochemicals; total phenolic contents in the range of 7.26 to 15.34 mg GAE/ g of extract and total flavonoid content in the range of 180.71 and 618. 96 mg QE/g of the extract. Furthermore, antioxidant assays were conducted, in which all the extracts showed fair DPPH radical scavenging activity in terms of EC50 values ranging from 0.48 to 0.92 mg/mL. The pseudostem extracts showed better ABTS radical scavenging activity in comparison to the inflorescence extract in all the varieties. However, inflorescence extracts exhibited a better reducing activity. Similarly, the extracts gave promising results for anti-diabetic activity, in terms of in vitro α-amylase and α-glucosidase inhibition activity. Phenolics present in the extracts were identified and quantified using the HPLC analysis. The present investigation clearly showed that banana by-products are a storehouse of bioactives, with great potential to be utilized as nutraceuticals in the food industry.
... The ferric reducing antioxidant power (FRAP) assay was conducted following the procedure of Benzie and Strain [35]. The 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay was conducted as reported by van den Berg et al. [36]. Trolox was used as control for all the experiments, and a Trolox standard curve was prepared to express the antioxidant capacity as mg equivalents of Trolox/g sample. ...
Porophyllum ruderale (P. ruderale) is a well-known Mexican plant from the group of “Quelites”, widely consumed plant species used for several food and medicinal purposes. As the production is very heterogeneous and the diverse agroclimatic conditions significantly impact the plant’s phytochemical composition, this research aimed to compare the phenolic compound composition and the antioxidant capacity of the P. ruderale plant from three different collection sites (Queretaro, Landa de Matamoros, and Arroyo Seco) in the State of Queretaro (Mexico). Plants collected from Queretaro displayed the lowest total phenolic compounds, flavonoids, and condensed tannins, reflected in a lower antioxidant capacity (DPPH, FRAP, ABTS), compared to the other collection places. Flavones (epicatechin and epigallocatechin gallate) were the most abundant (36.1–195.2 μg equivalents/g) phenolics quantified by HPLC-DAD, while 31 compounds were identified by UHPLC-DAD-QToF/MS-ESI. Most compounds were linked to biological mechanisms related to the antioxidant properties of the leaves. A PCA analysis clustered Landa de Matamoros and Arroyo Seco into two groups based on flavones, hydroxybenzoic acids, the antioxidant capacity (ABTS and DPPH), and total phenolic compounds, the main contributors to its variation. The results indicated contrasting differences in the polyphenolic composition of collected P. ruderale in Queretaro, suggesting the need to standardize and select plants with favorable agroclimatic conditions to obtain desirable polyphenolic compositions while displaying potential health benefits.
... Radical scavenging activities were measured by means of an ABTS assay (Cao et al., 2022;Lee et al., 2022a;Van den Berg et al., 1999). The ABTS radical cation solution was made by mixing potassium persulfate (2.6 mM) and ABTS (7.4 mM) in deionized water, which was then reacted for 24 h at RT. ...
... It is noted that Trolox was specifically chosen as the cargo because of its ability to scavenge free radicals and prevent oxidative damage in human dermal fibroblast (HDF) cells upon exposure to UV light. [29][30][31] The beauty of the Trolox⊂Azo@RSS-140 design is that it requires UV light activation -an environment and time when protection for HDF cells against the harmful effects of UV light is needed most and can be sustainably provided by released Trolox. ...
The concept of a molecular nano-valve is applied to a newly synthesized biocompatible hydrogen-bonded organic framework (HOF), termed RSS-140, in order to load, trap, and subsequently release an antioxidant on command. Specifically, we exploit the pore windows of RSS-140 (i.e., β-CD cavities) to first load and trap the antioxidant, Trolox, within the internal pores of the HOF (Trolox⊂RSS-140) and, to prevent it from leaching, utilize supramolecular chemistry to complex azobenzene (Azo) with β-CD (Trolox⊂Azo@RSS-140). The molecular nano-valve is fully realized upon exposing Trolox⊂Azo@RSS-140 to UV light with a specific wavelength, which induces Azo isomerization, Azo decomplexation from β-CD, and subsequent release of Trolox from the pores of RSS-140. The biocompatibility and non-toxicity of Trolox⊂Azo@RSS-140, together with the absolute control over the nano-valve opening, was established to yield a system that safely and slowly releases Trolox for longer-lasting antioxidant efficacy. As the field of supramolecular chemistry is rich with similar systems and many such systems can be used as building blocks to construct HOFs or other extended framework materials, we envision the molecular nano-valve concept to be applied widely for controllably delivering molecular cargo for diverse applications.
... The absorbance was measured at 734 nm, and a decrease in absorbance was observed [75]. The results of the DPPH or ABTS radical scavenging capacity of the antioxidants were mostly expressed in terms of the equivalent concentration of Trolox [76]. It is reported that the combination of chlorogenic acid and the proteins (zein, β-lactoglobulin, wheat gluten hydrolysate) showed enhanced capacities of scavenging DPPH and ABTS free radicals [30,42,46,48]. ...
Proteins have been extensively studied for their outstanding functional properties, while polyphenols have been shown to possess biological activities such as antioxidant properties. There is increasing clarity about the enhanced functional properties as well as the potential application prospects for the polyphenol–protein complexes with antioxidant properties. It is both a means of protein modification to provide enhanced antioxidant capacity and a way to deliver or protect polyphenols from degradation. This review shows that polyphenol–protein complexes could be formed via non-covalent or covalent interactions. The methods to assess the complex’s antioxidant capacity, including scavenging free radicals and preventing lipid peroxidation, are summarized. The combination mode, the type of protein or polyphenol, and the external conditions will be the factors affecting the antioxidant properties of the complexes. There are several food systems that can benefit from the enhanced antioxidant properties of polyphenol–protein complexes, including emulsions, gels, packaging films, and bioactive substance delivery systems. Further validation of the cellular and in vivo safety of the complexes and further expansion of the types and sources of proteins and polyphenols for forming complexes are urgently needed to be addressed. The review will provide effective information for expanding applications of proteins and polyphenols in the food industry.
... The ABTS + • radical inhibitor assay of extract obtained from UAE and HRE was carried out according to the methodology planned by Berg et al. with minor adjustments [31]. At first, phosphate-buffered saline (0.01 M, pH 7.4) was used to dissolve ABTS to a concentration of 7 mM. ...
Background
Besides fibre production, Corchorusolitorius is considered a nutritional and medicinal plant in traditional medicine. Its leaves possess different antioxidant compounds and display various biological properties. This study optimized the ultrasound-assisted extraction (UAE) parameters like temperature, time, solvent concentration, and liquid–solid ratio for total flavonoids (TFC) and total polyphenols content (TPC) from leaves employing response surface methodology (RSM).
Results
Findings demonstrated that under the optimized conditions, the highest extraction yield of total flavonoids (7.17 mg QE/g DW) and total polyphenol content (13.92 mg GAE/g DW) were recorded with the ethanol concentration 70.92%, temperature 68.06 °C, liquid–solid ratio 48.80 mL/mg, and ultrasound irradiation time 37.20 min. The optimum value of TFC (6.96 mg QE/g DW) and TPC (13.38 mg GAE/g DW) from the experiment of verification of optimized conditions was close to the predicted value and significantly superior to the conventional heat reflux extraction (HRE). LC–MS and HPLC analysis of the optimized extract from UAE demonstrated the existence of six major phenolic compounds, including chlorogenic acid, isoquercetin, hyperoside, adhyperforin, 1,3-di-O-caffeoylquinic acid, and 3,4-di-O-caffeoylquinic acid. Furthermore, the antioxidant test of the UAE leaves extract revealed an excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺•) and hydroxyl radical scavenging with IC50 values of 226.29, 199.53 and 402.02 µg/mL, respectively, compared to HRE with 336.31 µg/mL, 253.86 µg/mL, 520.08 µg/mL.
Conclusions
The developed optimization method could contribute to the good recovery of natural antioxidants from C. olitorius in the pharmaceuticals and food industries.
Graphical Abstract
... Cd-stress induces reactive oxygen species (ROS) and reduces antioxidant enzyme activity in plants (Farid, Shakoor et al. 2013). Trolox is a water-soluble form of vitamin E that has been standardized for its antioxidant properties, and its applicability to measure antioxidant capacity of lipophilic to hydrophilic compounds has been confirmed via ABTS radical decolorization assay (van den Berg, et al. 1999). ...
Though Zinc (Zn) supplementation can mitigate root-based Cadmium (Cd) uptake in plants, the impact of foliar-applied Zinc Oxide nanoparticles (ZnO NPs) on this process remains under-explored. This study investigates the influence of foliar-applied ZnO NPs on the growth of lettuce and its Cd uptake in Cd-contaminated soil in greenhouse setting. Green synthesized ZnO (G-ZnO) NPs (10 and 100 mg/L) using sweet potato leaf extracts were used, and compared to their efficacy commercially available ZnO (C-ZnO) NPs (100 mg/L). Scanning electron microscopy and Fourier-transform infrared spectroscopy were used for G-ZnO NPs characterization. Shoot dry weight, antioxidant activity, and chlorophyll content were all negatively affected by Cd but positively affected by ZnO NPs application. ZnO NPs application resulted in a notable reduction in lettuce Cd uptake, with the highest reduction (43%) observed at 100 mg/L G-ZnO NPs. In the lettuce shoot, Zn and Cd concentration showed a significant inverse correlation (R2 = 0.79-0.9, P < 0.05). This study offers insights into the impact of chemical and green synthesized ZnO NPs on enhancing crop growth under stress conditions, and their role in modulating Cd uptake in plants, indicating potential implications for sustainable agricultural practices.
... Once the radical solution was obtained, 3 mL of it was mixed with 150 µL of EE and the absorbance was read each minute until 6 measurements were made at 734 nm. This methodology was based on what was reported by [25]. ...
Common bean (Phaseolus vulgaris L.) is an important crop for food security and for national economics for several countries worldwide. One of the most important factors of risk in common bean production is the fungal disease anthracnose caused by Colletotrichum lindemuthianum, which, in some cases, causes complete yield losses; this kind of plant disease is usually managed through the application of chemical products such as fungicides that are commonly not accepted by society. This rejection is based on the relationship of pesticides with health damage and environmental contamination. In order to help in solving these drawbacks, the present work proposes the use of electrochemically activated salt solutions (EASSs) as a safer pathogen control agent in crops, due to it having shown an elicitor and biostimulant effect on plants. With this background, this manuscript presents in vitro results of the evaluation of the inhibitory effect for multiple bean pathogens and in vivo results of EASS in the common bean–Colletotrichum pathosystem by evaluation of the infection severity and defense activation, such as secondary metabolite production and antioxidant activity. EASS presence in growth media had a strong inhibitory effect at the beginning of experiments for some of the evaluated fungi. EASSs showed an effect against the development of the disease when applied in specific doses to prevent distress in plants.
... Para calcular los FST, TC y AT se prepararon curvas estándar de acido galico, catequina y cianidina 3 glucosido, respectivamente y se reportaron como mg/100 g. De igual manera, se determinó la capacidad antioxidante (TEAC) de acuerdo con Van den Berg et al., (1999). ...
The consumption of legumes, mainly beans, has been associated with a decrease in cardiovascular diseases, diabetes, obesity and some types of cancer. The per capita consumption of beans in Mexico has decreased rapidly in recent years. The objective was to generate artisan foods that include common bean flour and eval-uate their nutritional and functional quality. Bean products were made with bean/corn composite flours (50:50; 85:15) for totopos (tortilla chips) and churros, respec-tively. Totopos and churros turned out to be high-protein foods. The development of new bean-based products is of the utmost importance, not only because of their high fiber or protein content but also because of their high content of bioactive compounds.
... The ABTS +• radical inhibitor assay was implemented following the methodology stated by researcher with minor alterations [18]. ABTS was first solubilized in phosphate-buffered saline (PBS, 0.01 M, pH 7.4) with a final concentration 7 mM. ...
Different parts of Corchorus olitorius and C. capsularis possess different antioxidant compounds. This study investigated the phytochemical components and antioxidant capacities of ultrasound-assisted extraction of different plant parts of both species using spectrophotometry at various phenological stages. Results also indicate that leaves, stems and roots of C. olitorius at various growth stages showed higher phytochemical components and antioxidant potential compared to C. capsularis. The phytochemical components from roots to leaves in C. olitorius including total polyphenol 0.97–11.11 mg GAE/g DW, total flavonoid 0.99–7.78 mg QE/g DW and total tannin 4.02–26.89 TA E/g DW, whereas C. capsularis total polyphenol 1.04–7.93 mg GAE/g DW, total flavonoid 0.77–5.5.92 mg QE/g DW and total tannin content 3.17–22.73 TA E/g DW. C. olitorius produced overall 22.23%, 13.61%, 12.24% higher total polyphenol, total flavonoid and total tannin, respectively compare to C. capsularis. Different parts extract also significantly affected antioxidant capacities including DPPH, ABTS, and FRAP activity with values of 22.03–79.46% inhibition, 10.84–104.10 μmol TE/g DW, and 10.84–104.10 μmol Fe2+/g DW respectively for C. olitorius, while C. capsularis demonstrated 14.03–70.97% of DPPH inhibition, 9.16–95.60 μmol TE/g DW of ABTS and 5.31–71.82 μmol Fe2+/g DW of FRAP activity. Moreover, leaves of the flowering stage, young stems and aged roots of both species displayed a higher content of phytochemical and antioxidant activities than other growth stages. A positive correlation between the phytochemical and antioxidant potential indicated that phenolic constituents solely affected antioxidant activity. Thus, this study established that the plant's parts and phenological growth stages significantly influence the concentration of phytoconstituents and antioxidant activities, and determine the harvesting stages of the different organs of C. olitorius and C. capsularis for considerable medicinal importance as folk and industry.
... Once obtained the radical, 3mL of it were mixed with 150µL of EE and the absorbance was read at each minute until 6 measurements at 734 nm. This methodology was based on what was reported by [25]. ...
Common bean (Phaseolus vulgaris L.) is an important crop for food security and for national economics for several countries worlwide. One of the most important factors of risk in common bean production is the fungal disease anthracnose caused by Colletotrichum lindemuthianum, which in some cases, causes complete yield losses; this kind of plant disease is usually managed through the application of chemical products such as fungicides, that are commonly not accepted by society, this rejection is based on the relationship of pesticides with health damage and environmental contamination. In order to help in solving this drawbacks, the present work propose the use of Electrochemically Activated Salt Solutions(EASS) as a safer pathogen control agent in crops due to it have shown an elicitor and biostimulant effect on plants such as tobacco and apple. With this background, this manuscript presented in vitro results of the evaluation of the inhibitory effect for multiple bean pathogens and in vivo results of EASS in the common bean-Colletotrichum pathosystem by in vitro evaluations of the inhibitory effect for multiple bean pathogens and in vivo evaluation of the infection severity and defense activation such as secondary metabolites production and antioxidant activity. EASS presence in growth media had strong inhibitory effect, at beginning of experiment, for some of the evaluated fungi. EASS showed effect against the development of the disease when applied in specific doses to prevent distress in plants.
... The ABTS assay was based on the method of [32], slightly modified by [33]. Briefly, a radical solution (3.5 mM ABTS and 1.25 mM potassium persulfate) was prepared in sterile water and left to stand in the dark for 24 h. ...
Macrofungi are among the most promising sources of biologically active natural products with nutritional qualities and therapeutic values. In this work, the nutritional value of nine species of wild macrofungi from Ibague-Tolima (Colombia) was evaluated. In addition the antioxidant, antimicrobial and cytotoxic activities of an ethanol:water (70:30) extract of wild basidiomata were evaluated. The wild mushrooms’ nutritional potential showed that the genus Pleurotus and Lentinus have the best protein percentages, with 18.4% and 18.5%. The nine extracts evaluated managed to stabilize the two radicals evaluated; however, lower IC50 was found for Phellinus gilvus and Ganoderma australe extracts. The results showed that Trametes coccinea, Pleurotus floridanus and Ganoderma australe extracts were the most effective as antimicrobials, with high inhibition percentages against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Antifungal activity results against Rhizopus oryzae, Penicillium sp. and Aspergillus niger showed that the nine extracts were effective at the concentrations tested. Considering cell viability against isolated leukocytes, seven of the nine extracts showed percentages higher than 50% of cell viability. This research describes the nutritional value of nine wild macrofungi in Colombia and their potential for antimicrobial, cytotoxic and antioxidant activity.
... The Trolox equivalent antioxidant capacity in plasma was assayed as described by Van den Berg et al. [60]. Briefly, a 2,2 -azinobis-(3-ethylbenzthiazoline-6-sulfonate radical solution (ABTS − ) was prepared by mixing 2.5 mM 2,2 -azobis-(2-amidinopropane) and HCl (ABAP) with 20 mM ABTS stock solution in 100 mM phosphate buffer (pH 7.4), containing 150 mM NaCl (PBS). ...
Herein, we investigated the effect of fish oil supplementation combined with a strength-training protocol, for 6 weeks, on muscle damage induced by a single bout of strength exercise in untrained young men. Sixteen men were divided into two groups, supplemented or not with fish oil, and they were evaluated at the pre-training period and post-training period. We investigated changes before and 0, 24, and 48 h after a single hypertrophic exercise session. Creatine kinase (CK) and lactate dehydrogenase (LDH) activities, plasma interleukin-6 (IL-6) and C-reactive protein (CRP) levels, and the redox imbalance were increased in response to the single-bout session of hypertrophic exercises at baseline (pre-training period) and decreased during the post-training period in the control group due to the repeated-bout effect (RBE). The fish oil supplementation exacerbated this reduction and improved the redox state. In summary, our findings demonstrate that, in untrained young men submitted to a strength-training protocol, fish oil supplementation is ideal for alleviating the muscle injury, inflammation, and redox imbalance induced by a single session of intense strength exercises, highlighting this supplementation as a beneficial strategy for young men that intend to engage in strength-training programs.
... 489 Their qualities as antioxidants are often used as a means to quantifying phenol content in terms of total antioxidant capability (AOC). 490 Several assays have been developed in the food and live sciences due to the necessity for the assessment of antioxidant properties: the Folin−Ciocalteu (FC) test, 491−493 ABTS (2,2′azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, 494 ORAC (oxygen radical absorbance capacity), 495 FRAP (ferric-reducing antioxidant power), 496 CuPRAC (cupric ion reducing antioxidant capacity), 496 TEAC (trolox equivalent antioxidant capacity), 497 and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging. 494 None of these established methods are recognized as universal, 496,498,499 and the correct selection for the study of AOC remains difficult. ...
Many successful stories in enzyme engineering are based on the creation of randomized diversity in large mutant libraries, containing millions to billions of enzyme variants. Methods that enabled their evaluation with high throughput are dominated by spectroscopic techniques due to their high speed and sensitivity. A large proportion of studies relies on fluorogenic substrates that mimic the chemical properties of the target or coupled enzymatic assays with an optical read-out that assesses the desired catalytic efficiency indirectly. The most reliable hits, however, are achieved by screening for conversions of the starting material to the desired product. For this purpose, functional group assays offer a general approach to achieve a fast, optical read-out. They use the chemoselectivity, differences in electronic and steric properties of various functional groups, to reduce the number of false-positive results and the analytical noise stemming from enzymatic background activities. This review summarizes the developments and use of functional group probes for chemoselective derivatizations, with a clear focus on screening for enzymatic activity in protein engineering.
... Comparing different types of legumes, it has been clarified that the highest levels of presence of flavonoids are present in lentils, as opposed to chickpeas and green and yellow peas, while an intermediate value is reported for soybeans [55]. The tests are in this case reported according to the Trolox equivalent antioxidant capacity (TEAC), which is based on scavenging action of 2, 2 -azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical anions (ABTS) [56]. ...
... The DPPH radical scavenging activity was calculated as follows: DPPH radical scavenging activity (%) = [1 − (Abs sample /Abs blank )] × 100. The 2,2 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was measured according to Vander Berg et al. [13] with minor modifications. The ABTS stock solution was prepared with an absorbance of 0.70 ± 0.02 at 734 nm. ...
The supplementation of pig diets with exogenous enzymes is widely used with the expectation that it will improve the efficiency of nutrient utilization, thereby, improving growth performance. This study aims to evaluate the effects of a 0.1% (v/v) multi-enzyme (a mixture of arazyme (2,500,000 Unit/kg), xylanase (200,000 Unit/kg) and mannanase (200,000 Unit/kg)) supplementation derived from invertebrate symbiotic bacteria on pig performance. Here, 256 growing pigs were assigned to control and treatment groups, respectively. The treatment group exhibited a significantly reduced average slaughter age; the final body weight and average daily gain increased compared with that of the control group. In the treatment group, the longissimus muscle showed a remarkable decrease in cooking loss, shear force, and color values with increased essential and non-essential amino acid concentrations. Furthermore, the concentrations of mono- and polyunsaturated fatty acids in the treatment group increased. Feed additive supplementation increased the family of Ruminococcaceae and genera Lactobacillus, Limosilactobacillus, Turicibacter, and Oscillibacter, which play a positive role in the host physiology and health. Predicted metabolic pathway analysis confirmed that operational taxonomic units and predicted amino acid biosynthesis pathways were strongly associated. The results suggest that applying exogenous enzymes derived from invertebrate symbiotic bacteria enhances animal performance.
... In order to simplify the kinetic strategy measurements, several end-point methods were developed, in which media with preformed ABTS •+ were used [17][18][19]. In this case, the subsequent addition of the sample containing antioxidants produced a decoloration (bleaching) of the ABTS •+ [22,38,39]. This approach results in the method easiest to perform, eliminating the interaction of the antioxidant with the reactant enzymes, and making it suitable for high-throughput analysis. ...
ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) is a widely used compound for determining the total antioxidant capacity (TAC) of plant extracts, food, clinical fluids, etc. This photometric assay is based on the reduction by the presence of antioxidant compounds of a well-known metastable radical (ABTS•+) which can be formed via several different approaches and be used in many different determination methodologies such as automated photometric measures in microplates, clinical robots, valuable titrations, and previous liquid chromatographic separation. Another interesting aspect is that, in some cases, the ABTS/TAC method permits sequential hydrophilic and lipophilic antioxidant activity determinations, obtaining total antioxidant activity values through the summatory data of both types of antioxidants. In this work, we present a review of several aspects of the ABTS/TAC, highlighting the major achievements that have made this method so widely used, e.g., ABTS radical formation in hydrophilic or lipophilic reaction media, measurement strategies, automatization, and adaptation to high-throughput systems, as well as the pros and cons. Moreover, some recent examples of ABTS/TAC method applications in plant, human, and animal samples are discussed.
... It is used as a principle to measure the absorbance of a purple DPPH solution by changing its color to yellow after removing free radicals through hydrogen donation to substances containing hydroxyl radicals [57]. The antioxidative activity measurement using ABTS radicals is a principle of measuring absorbance by decolorizing a blue reaction solution after removing ABTS free radicals generated by the reaction with potassium persulfate by an antioxidant in the sample [58]. In recent studies, it has been reported that the antioxidant activity and phenolic contents increased when grain by-products were liquid-fermented using Lactobacillus strain [59][60][61]. ...
The purpose of this study was to optimize conditions of solid-phase fermentation of lactic acid bacteria to enhance GABA contents in grains. Optimal solid-phase fermentation conditions that could enhance the GABA content after fermenting Oryza sativa (brown rice) were investigated by changing the Lactobacillus strain, fermentation temperature, fermentation time, and inoculated bacteria number. Avena sativa, Cicer arietinum, and red and brown Lens culinaris were then fermented using the optimal solid-phase fermentation conditions to measure changes in GABA content and antioxidant activity. As a result of the experiment, the optimal solid-phase fermentation conditions to enhance the GABA contents in grains were: fermentation time, 48 h; amounts of bacteria, inoculating 5% of 1 × 107 CFU/mL of lactic acid bacteria; and fermentation temperature, 36 °C. When fermented under this condition, the GABA content increased from 4.64 mg/g to 6.93 mg/g (49.0%) compared to unfermented raw material. The results of the DPPH and ABTS radical scavenging activity assays confirmed that both the GABA content and radical scavenging activity were increased after fermentation. Such solid fermentation conditions developed in this study can be used to support the development of health functional food materials with enhanced GABA content and antioxidant activity.
... The developed methods for determining the antioxidant content are quite accurate and informative, but they have disadvantages and limitations, which mainly include the complexity of the methodology and equipment, and the high cost of instruments and reagents. The main disadvantage of optical methods for determining the antioxidant content, which include such well-known approaches as TEAC (Trolox equivalent antioxidant capacity) [5,6], TRAP (Total radical trapping parameter) [7,8], ORAC (Oxygen radical absorbance capacity) [9], FRAP (Ferric reducing antioxidant power) [10], CUPRAC (Cupric Reducing Antioxidant Capacity) [11], is the difficulty in studying turbid and colored samples. Many methods for assessing antioxidant properties use strong oxidizing agents, or the analysis is carried out in an acidic solution, which, again, makes it difficult to use them for the analysis of objects containing proteins and amino acids. ...
At present, the development of portable devices for the express assessment of the content of biologically active objects, such as antioxidants, is one of the relevant technological problems of modern chemistry, medicine, and engineering. The main advantages of such devices are the simplicity and rapidity of analysis, small volumes of analyte, as well as miniaturization of equipment, making it possible to carry out the on-site analysis and, thus, to take a step towards the personalized medicine. The potentiometric method using the K3[Fe(CN)6]/K4[Fe(CN)6] system, which in the laboratory-scale version proved to be the most accurate, reproducible, and express, was the basis for the developed prototypes of portable devices. In this study, two versions of prototypes of the portable device are proposed, namely, the open microcell with the 0.2 ml volume and the microfluidic device with flow control. The correctness of the antioxidant capacity (AOC) determination in both systems was confirmed by comparing the results of the "introduced-found" method on model solutions of antioxidants and their mixtures with the AOC results obtained in a standard laboratory electrochemical cell. The relative standard deviation did not exceed 10%. The AOC of some beverage industry was determined using the microfluidic device. The correlation coefficient of the results, obtained in the microfluidic device and the laboratory cell, was 0.90, which indicates good data convergence and the possibility of using the potentiometric method implemented in the microfluidic device to assess the AOC of multicomponent objects.
... β-carotene (1.5-2.0), vitamin C (1.1), α-tocopherol (0.9-1.0), and GABA (0.3-0.7) compared to trolox (1) in ABTS or DPPH assay [38][39][40]. In this study, vitamin C levels were found to increase as the contents of total carotenoids including lycopene increased. ...
Tomato is a widely distributed, cultivated, and commercialized vegetable crop. It contains antioxidant constituents including lycopene, tocopherols, vitamin C, γ-aminobutyric acid, phenols, and flavonoids. This study determined the contents of the antioxidant components and activities of the pulp with skin of ten regular, six medium-sized, and two small cherry tomato cultivars at red ripe (BR + 10) stage cultivated in Korea. The relationships among the Hunter color coordinates, the content of each component, and antioxidant activities were measured by Pearson’s correlation coefficients. As the a* value increased, the carotenoid and vitamin C contents increased, while the L* value, hue angle and tocopherol content decreased. As the b* value increased, the lycopene and total carotenoid contents decreased, and the flavonoid content in the hydrophilic extracts increased. The contents of vitamin C and total carotenoids including lycopene showed high positive correlations with the DPPH radical scavenging activities of both the lipophilic and hydrophilic extracts. Tocopherols and total phenolics in the hydrophilic and lipophilic extracts were not major positive contributors to the antioxidant activity. These findings suggest the quality standards for consumer requirements and inputs for on-going research for the development of better breeds.
... Antioxidant capacity evaluation. According to the method of Bondet and Van den Berg, radical scavenging activity was determined with some modifications (23,24). The 2,2-diphenyl-1-picryl hydrazyl (DPPH) solution (300 µM) was dissolved in ethyl alcohol. ...
The inflammatory defense response of macrophages is a natural protective reaction in the immune system. Antioxidant and anti-inflammatory activities are closely related. In addition, the cell signaling pathway regulating inflammation is associated with MAPK and NF-κB signaling pathway phosphorylation. The present study aimed to evaluate whether the ethyl acetate fraction from N. fruticans (ENF) has a modulatory role in the MAPK signaling pathway and inhibition of the IκB/NF-κB signaling pathways, including translocation of NF-κB p65. Antioxidant and anti-inflammatory activities are closely related. In addition, the cell signaling pathway regulating inflammation is associated with MAPK and NF-κB signaling pathway phosphorylation. The results revealed that ENF exhibited antioxidant capacity, attenuated the cytokine levels and blocked nitric oxide production. ENF downregulated cyclooxygenase-2 and inducible nitric oxide synthase expression. We hypothesized that ENF treatment alleviated the various proinflammatory mediators via IκB phosphorylation and transcription of NF-κB compared with the untreated control. In conclusion, the present study demonstrated that the inhibitory effect of ENF treatment was attributed to the inhibition of MAPK and Akt/IκB/NF-κB signaling pathways.
... Analyses were performed by using the method described by Berg et al. (1999) and modified by John and Shahidi (2010 ...
Abstract
Berries are highly valued crops due to their unique flavour, texture, colour and phytochemicals. They are rich in phenolic compounds which have been recognized as having beneficial health effects in humans. Phenolic compounds are present in the free, soluble ester and insoluble-bound forms; these were extracted using four different solvents {methanol–acetone–water (7:7:6, v/v/v), acetone-water (80: 20, v/v), methanol-water (70: 30, v/v), and water}. The insoluble-bound phenolics were procured after alkaline hydrolysis and subsequent extraction into diethyl ether-ethyl acetate. Phenolic extracts of each fraction were separately assayed for their antioxidant activity using several methods, namely oxygen radical absorbance capacity (ORAC), the reducing power capacity, as well as iron (II) chelation capacity, among others. There were significant differences in the total content of phenolics, flavonoids, and anthocyanins between blackberry, black raspberry, and blueberry seed meals. The bound phenolics contributed the highest proportion to the total contents of different classes of phenolics. Furthermore, blackberry seed meals had higher total antioxidant activity compared with black raspberry and blueberry seed meals in all assays employed. High-performance liquid chromatography−diode array detection−electrospray ionization multistage mass spectrometry (HPLC-DAD-ESI-MSn) was used to identify and quantify the phenolic compounds. Hydroxybenzoic and hydroxycinnamic acids, anthocyanins, flavonols, flavan-3-ols, and proanthocyanidins were identified and quantified in the aforementioned fractions. Extracts were found to contain various levels of phenolic compounds that were specific to each berry seed meal type.
The application of cold plasma as a pretreatment for extraction process is a recent development. This research
investigates the impact of cold plasma (CP) treatment on the extraction process of bioactive compounds from
black chokeberry samples. Utilizing a 12-h maceration process, various analyses, including total phenolic content
(TPC), antioxidant capacity (DPPH, ABTS+, CUPRAC assays), total monomeric anthocyanin content (TMA),
color parameters, and comprehensive mathematical modeling, were employed to assess the effectiveness of CP
treatment. The kinetic modeling with Peleg, Power Law, Elovic’s, and Two-site Kinetic Models emphasized the
critical role of CP treatment duration in the extraction process. This study indicates that the power-law kinetic
model provided the best fit for the experimental data from CP-treated samples, suggesting that this model most
accurately describes the extraction kinetics under the conditions tested. In summary, this investigation underlines the crucial role of mathematical modeling in understanding the dynamics of bioactive compound extraction under CP treatment.
The concept of a molecular nanovalve is applied to a synthesized biocompatible hydrogen-bonded organic framework (HOF), termed RSS-140, to load, trap, and subsequently release an antioxidant on command. Specifically, we exploit the pore windows of RSS-140 (i.e., β-CD cavities) to first load and trap the antioxidant, Trolox, within the internal pores of the HOF (Trolox⊂RSS-140) and, to prevent it from leaching, utilize supramolecular chemistry to complex azobenzene (Azo) with β-CD (Trolox⊂Azo@RSS-140). The molecular nanovalve is fully realized upon exposing Trolox⊂Azo@RSS-140 to UV light with a specific wavelength, which induces Azo isomerization, Azo decomplexation from β-CD, and subsequent release of Trolox from the pores of RSS-140. The biocompatibility and nontoxicity of Trolox⊂Azo@RSS-140, together with the absolute control over the nanovalve opening, were established to yield a system that safely and slowly releases Trolox for longer-lasting antioxidant efficacy. As the field of supramolecular chemistry is rich with similar systems and many such systems can be used as building blocks to construct HOFs or other extended framework materials, we envision the molecular nanovalve concept to be applied widely for controllably delivering molecular cargo for diverse applications.
Skin is the largest and outermost organ in the human body; it serves as a vital defense mechanism against various external threats. Therefore, it is crucial to maintain its health through protection against harmful substances and adequate moisture levels. This study investigates the anti‐inflammatory, antioxidant, and moisturizing properties of Oxyceros horridus Lour. (Oh‐EE) in human keratinocytes. Oh‐EE demonstrates potent antioxidant activity and effectively protects against oxidative stress induced by external stimuli such as UVB radiation and H2O2. Additionally, it exhibits significant anti‐inflammatory effects proven by its ability to downregulate the expression of pro‐inflammatory cytokines, namely COX‐2 and IL‐6. The study also explores the involvement of the AP‐1 pathway, highlighting the ability of Oh‐EE to suppress the expression of p38 and its upstream regulator, MKK3/6, under UVB‐induced conditions. Interestingly, Oh‐EE can activate the AP‐1 pathway in the absence of external triggers. Furthermore, Oh‐EE enhances skin moisture by upregulating the expression of key genes involved in skin hydration, namely HAS3 and FLG. These findings underscore the potential of Oh‐EE as a versatile ingredient in skincare formulations, providing a range of skin benefits. Further research is warranted to comprehensively understand the underlying mechanisms through which Oh‐EE exerts its effects.
The microencapsulation of bioactive extracts of Chilean papaya waste, including both seeds and skin, was investigated. Papaya waste extract microcapsules utilizing maltodextrin at 10% (MD10), 20% (MD20), and 30% (MD30) (w/v) as the wall material through the freeze-drying process were obtained, and subsequently their physicochemical, antioxidant, and antimicrobial properties were evaluated. The TPC efficiency and yield values achieved were more than 60% for the microencapsulated seed and skin extracts, respectively. The best results for phenolic and antioxidant compounds were found in the microencapsulated seed extract with MD20, with a value of 44.20 ± 3.32 EAG/g DW for total phenols and an antioxidant capacity of 12.0 ± 0.32 mol ET/g DW for the DPPH and 236.3 ± 4.1 mol ET/g DW for the FRAP assay. In addition, the seed and skin samples reduced ROS generation in H2O2-treated Hek293 cells. In terms of antimicrobial activity, values ranging from 7 to 15 mm of inhibitory halos were found, with the maximum value corresponding to the inhibition of S. aureus, for both microencapsulated extracts. Therefore, the successful microencapsulation of the waste bioactive extracts (seed and skin) with the demonstrated antimicrobial and antioxidant properties highlight the bioactivity from Chilean papaya waste resources.
The sustainable dyeing using root of Rumex japonicus Houttuyn (RJH) on silk has been accomplished without using a mordant. After dyeing the scoured silk, the sugar content and turbidity, the color characteristics, antioxidant property by radical scavenging assay, the antibacterial activities by bacteria reduction rate, the ultraviolet (UV) protection, and the heavy metal adsorption were analyzed. As a result, the sugar content of the RJH solution increased, and the turbidity decreased after dyeing. The color of dyed silk with RJH showed high b* (yellowness) values, and the color fastness showed moderate grades 3. The antioxidant and antibacterial activities showed 89% or more and 96.8% reduction rate in Staphylococcus aureus, respectively. In addition, UV protection was also excellent at 96.4%. In particular, the content of residual heavy metal ion decreased from 6.796 mg/L to 0.655 mg/L, indicating excellent heavy metal adsorption.
Skin photoaging due to ultraviolet B (UVB) exposure generates reactive oxygen species (ROS) that increase matrix metalloproteinase (MMP). Chlorin e6-photodynamic therapy (Ce6-PDT), in addition to being the first-line treatment for malignancies, has been shown to lessen skin photoaging, while curcumin is well known for reducing the deleterious effects of ROS. In the current study, PDT with three novel Ce6-curcumin derivatives, a combination of Ce6 and curcumin with various linkers, including propane-1,3-diamine for Ce6-propane-curcumin; hexane-1,6-diamine for Ce6-hexane-curcumin; and 3,3′-((oxybis(ethane-2,1-diyl))bis(oxy))bis(propan-1-amine) for Ce6-dipolyethylene glycol (diPEG)-curcumin, were studied for regulation of UVB-induced photoaging on human skin fibroblast (Hs68) and mouse embryonic fibroblast (BALB/c 3T3) cells. We assessed the antiphotoaging effects of Ce6-curcumin derivatives on cell viability, antioxidant activity, the mechanism of matrix metalloproteinase-1 and 2 (MMP-2) expression, and collagen synthesis in UVB-irradiated in vitro models. All three Ce6-curcumin derivatives were found to be non-phototoxic in the neutral red uptake phototoxicity test. We found that Ce6-hexane-curcumin-PDT and Ce6-propane-curcumin-associated PDT exhibited less cytotoxicity in Hs68 and BALB/c 3T3 fibroblast cell lines compared to Ce6-diPEG-curcumin-PDT. Ce6-diPEG-curcumin and Ce6-propane-curcumin-associated PDT showed superior antioxidant activity in Hs68 cell lines. Further, in UVB-irradiated in vitro models, the Ce6-diPEG-curcumin-PDT greatly attenuated the expression levels of MMP-1 and MMP-2 by blocking mitogen-activated protein kinases (MAPKs), activator protein 1 (AP-1), and tumor necrosis factor-α (NF-κB) signaling. Moreover, Ce6-diPEG-curcumin effectively inhibited inflammatory molecules, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, while accelerating collagen synthesis. These results demonstrate that Ce6-diPEG-curcumin may be a potential therapy for treating skin photoaging.
Unlabelled:
Pollutant exposure due to industrial development increases oxidative stress in human bodies. Dietary intake of antioxidant shows a protective effect against oxidative damage induced by oxidative stress. Therefore, the development of natural antioxidants is needed. In this study, the antioxidant activities of some Nepali medicinal plant extracts were measured. Using Rose bengal and 3,3',5,5'-tetramethylbenzidine, a novel assay was utilized to evaluate the singlet oxygen scavenging capacity, and showed a strong correlation with other antioxidant assays. Also, antioxidant capacities based on four assays including the singlet oxygen scavenging assay were highly correlated (≥ 0.858) with the total phenolic contents in the medicinal plant extracts. Among the selected extracts, Persicaria capitata, Elaphoglossum marginatum and Eurya acuminata showed the highest antioxidant capacities. Overall, this study presents a novel approach for evaluating singlet oxygen scavenging capacity, and performed a screening of antioxidant capacities of 54 Nepali herbal medicines.
Supplementary information:
The online version contains supplementary material available at 10.1007/s10068-022-01175-z.
Background and objectives:
The occurrence of non-melanoma and melanoma skin cancers is currently increasing rapidly with one in every three cancers diagnosed as a skin cancer. A useful strategy to control the progression of skin cancer could be the use of plant flavonoids that suppress pro-inflammatory cytokines involved in tumor initiation and progression. In this study, the anti-inflammatory and antioxidant activity of undifferentiated callus extracts from Plantago major L, Silybum marianum L and Rhodiola rosea L was investigated both in normal and malignant skin cells.
Methods:
Antioxidant activity of the extracts was analyzed by using the Trolox Equivalent Antioxidant Capacity (TEAC) assay. High-Performance Thin-Layer Chromatography (HPTLC) was performed to demonstrate the phytochemical profile, and the total flavonoid content was analyzed with an aluminum chloride colorimetric method. The anti-inflammatory effect was investigated by cell treatments using the plant extracts. Thereafter, the possible suppression of induced IL-6 response was measured from the cultured skin cancer cell lines A2058 and A431, and normal primary keratinocytes with Enzyme-Linked Immunosorbent Assay (ELISA).
Results:
The HPTLC analysis assessed that the extracts contained a complex phytochemical profile that was rich in phenolic and flavonoid compounds. Dose response assays showed that concentrations between 15 and 125 μg/mL of all three plant extracts could be used to investigate an effect on the IL-6 production. The S. marianum extract had the most pronounced anti-inflammatory effect, which significantly inhibited induced IL-6 production in both normal keratinocytes and skin cells derived from epidermal carcinoma. The extract from S. marianum also had the highest flavonoid content and showed the highest antioxidant activity of the three extracts tested.
Conclusion:
All in all, we have confirmed that undifferentiated callus extracts of S. marianum possess properties such as antioxidant and anti-inflammatory activities in both normal and malignant keratinocytes, and thus could be a promising agent controlling the pro-inflammatory IL-6 production.
The succulent plant Aeonium sedifolium leaves contain several compounds that are of interest for their cosmetic uses on the skin. This study measured the inhibitory effects of enzyme production and antioxidant, astringent effects and skin wrinkles using Aeonium sedifolium leaves (ASL). The total phenolics compounds (TPC) content of ASL under optimal extraction conditions was 34.49 mg/g for hot water extract (ASLW) and 61.64 mg/g for 50% ethanol extract (ASLE). The ASLW and ASLE extracts were freeze-dried, powdered, and used as solids. TPC content, 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging activity, and 2,2’-azinobis (3-ethylben-zothiazoline 6-sulfonate) (ABTS) radical inhibition of the ASL phenolics were tested. The DPPH radical scavenging activities of ASLW and ASLE were tested at a TPC of 100 μg/mL. ABTS radical inhibition showed antioxidant activity of 100.00% in ASLW and ASLE, and the antioxidant protection factor of ASLW and ASLE was 1.07 and 1.22, respectively. The thiobarbituric acid-reactive substance (TBARS) inhibitory activity of ASLW and ASLE was 77.00%. The elastase inhibitory activity of ASLE was 69.03%, and collagenase inhibition activity for ASLW and ASLE was 29.82% and 54.76%, respectively. The astringent effect of ASLE was 89.82% at a TPC of 200 μg/mL. Thus, we concluded that ASL has the potential as a functional cosmetic ingredient with anti-aging effects on the skin.
Alkaline-extracted walnut protein isolates showed relatively poor solubility and emulsifying properties in many previous studies. However, whether they can be used as potential emulsifiers to stabilize high internal phase emulsions (HIPEs) remains unknown. Herein, walnut protein isolates were prepared by alkaline extraction from walnut kernels with or without pellicles (named PAWPI and AWPI, respectively). PAWPI conjugated with pellicle polyphenols showed improved solubility and higher antioxidant capacity than AWPI. HIPEs were fabricated via a one-step method using AWPI or PAWPI as the sole protein emulsifier. HIPEs (oil fraction of 0.8, with 0.1% β-carotene) could be stabilized by PAWPI at a relatively low concentration of 0.2% (w/v), while at least 1% (w/v) AWPI was required to effectively stabilize HIPEs. HIPEs stabilized by PAWPI had smaller oil droplet sizes than those stabilized by AWPI. Rheological analysis indicated that PAWPI-stabilized HIPEs showed higher viscosity and better viscoelasticity than AWPI-stabilized HIPEs. Large-amplitude oscillation shearing analysis suggested that PAWPI-stabilized HIPEs were stiffer but more brittle than AWPI-stabilized HIPEs. Moreover, both PAWPI- and AWPI-stabilized HIPEs exhibited good storage stability and were relatively stable against heat treatment and ionic strength. PAWPI-stabilized HIPEs showed a higher protective capacity for encapsulated β-carotene than AWPI-stabilized HIPEs. In addition, PAWPI-stabilized HIPEs showed good 3D printability and could be used as a promising edible ink.
In order to explore novel blood pressure-regulating substances and fulfill the high-value utilization of various edible flowers, the inhibitory activities of aqueous solutions of 22 edible flower petals extracts on renin and angiotensin converting enzyme (ACE) were investigated. The results showed that almost all the aqueous sample extracts demonstrated an inhibition of renin and/or ACE. The Rosa rugosa Thunb. (IC50 = 25.13 and 60.00 μg mL-1) and Paeonia suffruticosa Andr. (IC50 = 50.54 and 292.47 μg mL-1) extracts showed prominent dual inhibitory activity against renin and ACE. The antioxidant activities and content of total phenols and flavonoids of the aqueous sample extracts were tested, because the oxidative damage of blood vessels is closely related to the occurrence and development of hypertension. The correlation between the contents of total phenolic substances and flavonoids, and the functional activities was analyzed. Renin and ACE inhibitory activities, DPPH and ABTS free radical scavenging capacity, and iron reduction ability of different sample extracts were significantly positively correlated with the total phenolic content (p <0.01), whereby the correlation coefficients were 0.87, 0.83, 0.93, 0.95, and 0.93 respectively. It was indicated that the aqueous phenolic compounds in Rosa rugosa Thunb and Paeonia suffruticosa Andr extracts tended to show stronger renin and ACE inhibitory activities, and exhibited a potential prospect for auxiliary blood pressure control.
The chemical composition, content of cholesterol, retinol and α-tocopherol, and the total antioxidant capacity of different tissues from wild beavers were investigated. The total phenolic contents and free radical scavenging activity (DPPH and ABTS assays) were analysed spectrophotometrically, and fat-soluble vitamins were quantified using high-performance liquid chromatography. The type of tissue (skeletal muscle from loin and hind leg vs. adipose tissue from subcutaneous fat and tail) significantly affected content of all chemical components. The concentration of cholesterol was not related to total fat content. The retinol and α-tocopherol contents (µg/100 g) were significantly higher in the tail (13.0 and 391.2) and subcutaneous fat (12.2 and 371.3) compared to skeletal muscles (as an average 9.1 and 361.4). Among all tissues the tail showed significantly the highest values of DPPH (3.07 mM TE/100 g), ABTS (3.33 mM TE/100 g), and total phenolics (TPC, 543.7 mg GAE/100 g). The concentration of retinol was positively correlated with α-tocopherol (0.748, p < 0.001), and both vitamins were very strongly correlated with DPPH (0.858 and 0.886, p < 0.001), ABTS (0.894 and 0.851, p < 0.001), and TPC (0.666 and 0.913, p < 0.001). The principal component analysis proved that moisture, ash, and protein contents were representative for skeletal muscles, whereas, retinol, α-tocopherol, ABTS and DPPH accurately described the antioxidant capacity of tissue from the tail.
Trolox-C (TXC) is a water-soluble analogue of α-tocopherol that reduces the metal-bound superoxo complex, [(NH3)5Co(µ-O2)Co(NH3)5]5+ (SOC) in water-ethanol media. In aqueous-acid media ([H+] = 0.02–0.70 M), TXC quantitatively reduces SOC under the pseudo first-order reaction condition where the concentration of TXC, [TXC] was at least ten times or more than that of [SOC]. Variations in media ionic strength suggests for the reaction between two cationic species and a positive kinetic isotope effect (kH/kD <1) indicates for a pre-equilibrium step of protonation of the pyran-oxygen of TXC. Both TXC and the protonated TXC, i.e., TXCH are the potential reductants under the experimental range of media acidity. The reduction of SOC takes place through the single electron transfer (SET) and the kinetic analysis yields the value for second-order rate constants for TXC and TXCH as 9.7 and 3.6×103 M-1s-1 at 15 ºC.
A relatively simple and widely applied method for quantitating the total antioxidant capacity of body fluids and drug solutions based on the absorbance of the ABTS radical cation was evaluated. In this assay, the end-point is an antioxidant-induced decrease in absorbance at a fixed time. This decrease is used as an index of total antioxidant capacity. It is shown that Trolox, potassium cyanide and quercetin all decrease the absorbance of ABTS radical cations at a fixed time, but by different mechanisms. Trolox scavenges the ABTS radical, potassium cyanide inhibits radical formation, while quercetin acts by both mechanisms. Using this method antioxidant capacity may be overestimated, due to both a scavenger effect and an effect on the rate of ABTS oxidation. To distinguish between these effects, a post-addition assay was used in which the sample is added when the formation of radicals is stable. Using post- addition assay conditions enables discrimination between effects on radical scavenging and on the radical formation, two major mechanisms for antioxidant action. In extrapolating the results to an in vivo situation it should be questioned: (i) whether the peroxidase process does indeed mimic the process of radical formation in vivo, and (ii) whether the ABTS radicals do resemble the radical species involved in an in vivo situation. Results obtained in the ABTS radical-based methods should therefore be reviewed critically before the antioxidant capacity can be assessed.
Background. Epidemiologic evidence indicates that diets high in carotenoid-rich fruits and vegetables, as well as high serum levels of vitamin E (alpha-tocopherol) and beta carotene, are associated with a reduced risk of lung cancer. Methods. We performed a randomized, double-blind, placebo-controlled primary-prevention trial to determine whether daily supplementation with alpha-tocopherol, beta carotene, or both would reduce the incidence of lung cancer and other cancers. A total of 29,133 male smokers 50 to 69 years of age from southwestern Finland were randomly assigned to one of four regimens: alpha-tocopherol (50 mg per day) alone, beta carotene (20 mg per day) alone, both alpha-tocopherol and beta carotene, or placebo. Follow-up continued for five to eight years. Results. Among the 876 new cases of lung cancer diagnosed during the trial, no reduction in incidence was observed among the men who received alpha-tocopherol (change in incidence as compared with those who did not, -2 percent; 95 percent confidence interval, -14 to 12 percent). Unexpectedly, we observed a higher incidence of lung cancer among the men who received beta carotene than among those who did not (change in incidence, 18 percent; 95 percent confidence interval, 3 to 36 percent). We found no evidence of an interaction between alpha-tocopherol and beta carotene with respect to the incidence of lung cancer. Fewer cases of prostate cancer were diagnosed among those who received alpha-tocopherol than among those who did not. Beta carotene had little or no effect on the incidence of cancer other than lung cancer. Alpha- tocopherol had no apparent effect on total mortality, although more deaths from hemorrhagic stroke were observed among the men who received this supplement than among those who did not. Total mortality was 8 percent higher (95 percent confidence interval, 1 to 16 percent) among the participants who received beta carotene than among those who did not, primarily because there were more deaths from lung cancer and ischemic heart disease. Conclusions. We found no reduction in the incidence of lung cancer among male smokers after five to eight years of dietary supplementation with alpha-tocopherol or beta carotene. In fact, this trial raises the possibility that these supplements may actually have harmful as well as beneficial effects.
1. Oxygen is a toxic gas - an introductionto oxygen toxicity and reactive species 2. The chemistry of free radicals and related 'reactive species' 3. Antioxidant defences Endogenous and Diet Derived 4. Cellular responses to oxidative stress: adaptation, damage, repair, senescence and death 5. Measurement of reactive species 6. Reactive species can pose special problems needing special solutions. Some examples. 7. Reactive species can be useful some more examples 8. Reactive species can be poisonous: their role in toxicology 9. Reactive species and disease: fact, fiction or filibuster? 10. Ageing, nutrition, disease, and therapy: A role for antioxidants?
There is currently much interest in phytochemicals as bioactive components of food. The roles of fruit, vegetables and red wine in disease prevention have been attributed, in part, to the antioxidant properties of their constituent polyphenols (vitamins E and C, and the carotenoids). Recent studies have shown that many dietary polyphenolic constituents derived from plants are more effective antioxidants in vitro than vitamins E or C, and thus might contribute significantly to the protective effects in vivo. It is now possible to establish the antioxidant activities of plant-derived flavonoids in the aqueous and lipophilic phases, and to assess the extent to which the total antioxidant potentials of wine and tea can be accounted for by the activities of individual polyphenols.
The characteristics of the colorless ABTS[sup 2[minus]] ion [ABTS = 2,2[prime]-azinobis(3-ethylbenzothiazoline-6-sulfonate)] and of the persistent, intensely-colored radical ABTS[sup [sm bullet][minus]] have been examined since some reported values are in disagreement. The standard reduction potentials of ABTS[sup [sm bullet][minus]]/ABTS[sup 2[minus]] and ABTS[sup [sm bullet][minus]]/HABTS[sup [minus]] are 0.68 and 0.81 V vs NHE, respectively. A second wave in the CV is associated with ABTS[sup 0]/ABTS[sup [sm bullet][minus]], E[sub 1/2] = 1.09 V. The pH dependence of E[degrees] leads to pK[sub a](HABTS[sup [minus]]) = 2.2 [+-] 0.3; a spectrophotometric pH titration gives 2.08 [+-] 0.02 at [mu] = 1.0 M. The protonated radical HABTS[sup [sm bullet]] was not detected (pK[sub a] < 0), consistent with the higher acidity of the radical relative to its reduced precursor. The EPR spectrum of ABTS[sup [sm bullet][minus]] shows a multiline spectrum centered at g = 2.0036 [+-] 0.0004 from the hyperfine coupling to two sets of two equivalent nitrogens as well as six aromatic hydrogens. Line broadening of the methyl and aromatic resonances of ABTS[sup 2[minus]] in the presence of the radical gives an electron exchange rate constant of (4 [+-] 1) [times] 10[sup 7] L mol[sup [minus]] s[sup [minus]] for ABTS[sup 2[minus]]/ABTS[sup [sm bullet][minus]] in neutral aqueous solution. In 1.0 M perchloric acid, Fe[sup 3+] oxidizes HABTS[sup [minus]] (k = 1.30 [times] 10[sup 2] L mol[sup [minus]1] s[sup [minus]1]) and Fe[sup 2+] reduces ABTS[sup [sm bullet][minus]] (k = 7.5 [times] 10[sup 2] L mol[sup [minus]1] s[sup [minus]1]). Although the equilibrium constant K = k[sub f]/k[sub r] for the reaction agrees with that predicted by the measured potentials, the individual rate constants are much lower than those one calculates from the Marcus cross-relation, which is typical for reactions of Fe(H[sub 2]O)[sub 6][sup 3+] and Fe(H[sub 2]O)[sub 6][sup 2+]. 28 refs., 6 figs., 2 tabs.
The total antioxidant-activity (TAA) has been evaluated as a marker of the deterioration of apple juice during storage. Unfortified juice, juice fortified with vitamin C, and an apple ''drink'' (6% juice), to which vitamin C (300 ppm) is added during manufacture, were evaluated. Vitamin C activity represented a minor fraction of the TAA (ca. 1%) of ''longlife'' apple juice, with chlorogenic acid and phloretin glycosides as the major identifiable antioxidants (ca. 32% and 11% of the TAA, respectively). Antioxidant activity ascribable to these substances was stable under the storage conditions examined, whereas ascorbic acid added into the juice was unstable; in fortified whole apple juice the TAA value correlated significantly with the decline in the ascorbic acid concentration, while in the apple drink there was a direct relationship between TAA and ascorbate.
The total reactive antioxidant potential (TRAP) of white and red wines is evaluated by a procedure based on the bleaching of pre-formed 2,2′-azinodi-(3-ethylbenzothiazoline-6-sulfonic acid radical cations. All the red wines considered presented TRAP values between 25.1 and 33.3 mM. The values obtained for the white wines were considerably smaller, ranging from 2.9 to 5.2 mM. The antioxidant potential measured in the wines is associated to the presence of compounds of low hydrophobicity.
Lycopene, a biologically occurring carotenoid, exhibits the highest physical quenching rate constant with singlet oxygen (kq = 31 X 10(9) M-1 s-1), and its plasma level is slightly higher than that of beta-carotene (kq = 14 X 10(9) M-1 s-1). This is of considerable general interest, since nutritional carotenoids, particularly beta-carotene, and other antioxidants such as alpha-tocopherol (kq = 0.3 X 10(9) M-1 s-1) have been implicated in the defense against prooxidant states; epidemiological evidence reveals that such compounds exert a protective action against certain types of cancer. Also, albumin-bound bilirubin is a known singlet oxygen quencher (kq = 3.2 X 10(9) M-1 s-1). Interestingly, those compounds with low kq values occur at higher plasma levels. When these differences are taken into account, the singlet oxygen quenching capacities of lycopene (0.7 microM in plasma), beta-carotene (0.5 microM in plasma), albumin-bound bilirubin (15 microM in plasma), and alpha-tocopherol (22 microM in plasma) are of comparable magnitude.
The Total (Peroxyl) Radical-trapping Antioxidant Parameter (TRAP) of six freshly prepared human plasma samples and 45 frozen plasma samples has been determined. It is shown that contributions from urate (35-65%), plasma proteins (10-50%), ascorbate (0-24%) and vitamin E (5-10%) to TRAP account for all of the peroxyl radical-trapping antioxidant activity in the majority of the samples. The changes in concentrations of the plasma antioxidants during peroxyl radical attack show that the first line of defense is provided by the plasma sulfhydryl groups, even urate being spared during the initial stages of the reaction. The modes of action of all of these plasma antioxidants and possible interactions between them are discussed, with particular emphasis on the abilities of the water-soluble antioxidants to regenerate or spare the only lipid-soluble antioxidant, vitamin E.
The purpose of this investigation was to establish the relative antioxidant activities in vitro of the flavanolic polyphenols, the catechins, and catechin-gallate esters. The relative antioxidant potentials were measured against radicals generated in the aqueous phase and against propagating lipid peroxyl radicals. The results show that in the aqueous phase their order of effectiveness as radical scavengers is epicatechin gallate (ECG) > epigallocatechin gallate (EGCG) > epigallocatechin (EGC) > gallic acid (GA) > epicatechin congruent to catechin; against propagating lipid peroxyl radical species, epicatechin and catechin are as effective as ECG and EGCG, the least efficacious being EGC and GA. This is consistent with their relative abilities to protect against consumption of LDL alpha-tocopherol. The results are discussed in the context of the most relevant antioxidant constituents of green tea extracts.
The role of antioxidants in nutrition is an area of increasing interest. Antioxidants are used (1) to prolong the shelf life and maintain the nutritional quality of lipid-containing foods, and (2) to modulate the consequences of oxidative damage in the human body. This review discusses what an antioxidant is and how the properties of antioxidants may be characterized.
1. A new method has been developed for measuring the total antioxidant capacity of body fluids and drug solutions, based on the absorbance of the ABTS*+ radical cation.
2. An automated method for use on a centrifugal analyser, as well as a manual method, is described.
3. The procedure has been applied to physiological antioxidant compounds and radical-scavenging drugs, and an antioxidant ranking was established based on their reactivity relative to a 1.0 mmol/l Trolox standard.
4. The Trolox equivalent antioxidant capacity of plasma from an adult reference population has been measured, and the method optimized and validated.
5. The method has been applied to investigate the total plasma antioxidant capacity of neonates and how this may be compromised in prematurity.
Observational studies suggest that people who consume more fruits and vegetables containing beta carotene have somewhat lower risks of cancer and cardiovascular disease, and earlier basic research suggested plausible mechanisms. Because large randomized trials of long duration were necessary to test this hypothesis directly, we conducted a trial of beta carotene supplementation.
In a randomized, double-blind, placebo-controlled trial of beta carotene (50 mg on alternate days), we enrolled 22,071 male physicians, 40 to 84 years of age, in the United States; 11 percent were current smokers and 39 percent were former smokers at the beginning of the study in 1982. By December 31, 1995, the scheduled end of the study, fewer than 1 percent had been lost to follow-up, and compliance was 78 percent in the group that received beta carotene.
Among 11,036 physicians randomly assigned to receive beta carotene and 11,035 assigned to receive placebo, there were virtually no early or late differences in the overall incidence of malignant neoplasms or cardiovascular disease, or in overall mortality. In the beta carotene group, 1273 men had any malignant neoplasm (except nonmelanoma skin cancer), as compared with 1293 in the placebo group (relative risk, 0.98; 95 percent confidence interval, 0.91 to 1.06). There were also no significant differences in the number of cases of lung cancer (82 in the beta carotene group vs. 88 in the placebo group); the number of deaths from cancer (386 vs. 380), deaths from any cause (979 vs. 968), or deaths from cardiovascular disease (338 vs. 313); the number of men with myocardial infarction (468 vs. 489); the number with stroke (367 vs. 382); or the number with any one of the previous three end points (967 vs. 972). Among current and former smokers, there were also no significant early or late differences in any of these end points.
In this trial among healthy men, 12 years of supplementation with beta carotene produced neither benefit nor harm in terms of the incidence of malignant neoplasms, cardiovascular disease, or death from all causes.
The purpose of this study was to assess the relative antioxidant activities of a range of carotenes and xanthophylls through the extent of their abilities to scavenge the ABTS(.+) radical cation. The results show that the relative abilities of the carotenoids to scavenge the ABTS(.+) radical cation are influenced by the presence of functional groups with increasing polarities, such as carbonyl and hydroxyl groups, in the terminal rings, as well as by the number of conjugated double bonds.
The accumulation of 2.2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical catalyzed by peroxidase can be inhibited by the presence of L-ascorbic acid in the reaction medium, this inhibition delaying the accumulation of the ABTS radical and giving rise to a lag time. A kinetic approach to explain this lag time is presented, which also makes it possible to determine the amount of L-ascorbic acid in the reaction medium. The stoichiometry of the system was determined as 1 mol of L-ascorbic reducing 2 mol of ABTS radicals. L-Ascorbic acid is not the only compound to have this ability, since other antioxidant compounds also react with the ABTS radical. We studied the ABTS/H2O2/horseradish peroxidase system in the presence of L-ascorbic acid and other antioxidant compounds. The influence of such factors as pH, enzyme concentration, and L-ascorbic acid concentration was studied. A good correlation between the lag time and the L-ascorbic acid present in the medium was observed, and under optimal conditions, the method could determine as little as 0.65 nmol of L-ascorbic acid. Based on our findings, we propose a method to measure the total antioxidant activity of different compounds related to L-ascorbic acid and apply this method to determining the total antioxidant activity present in fruit juices.
This study introduces a simple direct antioxidant assay, based on the reduction of the ABTS.+ radical cation, and compares it with the myoglobin/ABTS.+ assay. The methods give closely similar results, establishing that the antioxidants studied to date in the latter assay act by scavenging the ABTS.+ radical cation and not by inhibiting its formation through reduction of ferryl myoglobin or reaction with H2O2.
Shortcomings of an auto-mated assay for total antioxidant status in biological ¯uids Spectro-scopic parameters, electrode potentials, acid ionisation constants, and electron exchange rates of the 2,2 H -azinobis(3-ethylbenzothia-zoline-6-sulfonate) radicals and ions
- D Scho®eld
- J M Braganza
- ±
- S L Scott
- W Chen
- A Bakac
- J H Espenson
Scho®eld, D., & Braganza, J. M. (1996). Shortcomings of an auto-mated assay for total antioxidant status in biological ¯uids. Clinical Chemistry, 42, 1712±1714. Scott, S. L., Chen, W., Bakac, A., & Espenson, J. H. (1993). Spectro-scopic parameters, electrode potentials, acid ionisation constants, and electron exchange rates of the 2,2 H -azinobis(3-ethylbenzothia-zoline-6-sulfonate) radicals and ions. J. Phys. Chem, 97, 6710±6714.
- C H Hennekens
- J Buring
- J E Manson
- M Stampfer
- B Rosner
- R Cook
- C Belanger
- La Motte
- F Gaziano
- J M Ridber
- P M Willet
- W Peto
Hennekens, C. H., Buring, J., Manson, J. E., Stampfer, M., Rosner,
B., Cook, R., Belanger, C., La Motte, F., Gaziano, J. M., Ridber,
P. M., Willet, W., & Peto, R. (1994). New England Journal of Medicine 334, 1145-1149.
(The a-tocopherol b-carotene cancer prevention study group). The eect of vitamin E and b-carotene on the incidence of lung cancer, other cancers in male smokers
ATBC (1994). (The a-tocopherol b-carotene cancer prevention study
group). The eect of vitamin E and b-carotene on the incidence of
lung cancer, other cancers in male smokers. New England Journal of
Medicine, 330, 1029±1035.
- C H Hennekens
- J Buring
- J E Manson
- M Stampfer
- B Rosner
- R Cook
- C Belanger
- F La Motte
- J M Gaziano
- P M Ridber
- W Willet
- R Peto
Hennekens, C. H., Buring, J., Manson, J. E., Stampfer, M., Rosner,
B., Cook, R., Belanger, C., La Motte, F., Gaziano, J. M., Ridber,
P. M., Willet, W., & Peto, R. (1994). New England Journal of Medicine 334, 1145-1149.